Transparent thermoplastic resin and method of preparing the same

Abstract

The present invention relates to a transparent thermoplastic resin. More particularly, the present invention relates to a transparent thermoplastic resin, including a random copolymerization block prepared by polymerizing 50 to 80% by weight of an aromatic vinyl compound, 10 to 30% by weight of a vinyl cyanide compound, and 0 to 15% by weight of (meth)acrylic acid alkyl ester; and an aromatic vinyl compound block prepared by polymerizing 1 to 10% by weight of an aromatic vinyl compound, a transparent thermoplastic resin composition including the transparent thermoplastic resin, and methods of preparing the aromatic vinyl compound and transparent thermoplastic resin.

The invention claimed is: 
     
       1. A transparent thermoplastic resin, comprising:
 a random copolymerization block prepared by polymerizing 50 to 80% by weight relative to a weight of the transparent thermoplastic resin of an aromatic vinyl compound, 10 to 30% by weight relative to the weight of the transparent thermoplastic resin of a vinyl cyanide compound, and greater than 0% up to 15% by weight relative to the weight of the transparent thermoplastic resin of (meth)acrylic acid alkyl ester; and 
 an aromatic vinyl compound block prepared by polymerizing 1 to 10% by weight relative to the weight of the transparent thermoplastic resin of an aromatic vinyl compound. 
 
     
     
       2. The transparent thermoplastic resin according to  claim 1 , wherein the aromatic vinyl compound block is bonded to one end or both ends of the random copolymerization block. 
     
     
       3. The transparent thermoplastic resin according to  claim 1 , wherein the transparent thermoplastic resin has a refractive index of 1.5675±0.0040. 
     
     
       4. The transparent thermoplastic resin according to  claim 1 , wherein the transparent thermoplastic resin has a weight average molecular weight of 185,000 to 300,000 g/mol. 
     
     
       5. A method of preparing a transparent thermoplastic resin, the method comprising:
 a first polymerization step of polymerizing 50 to 80% by weight relative to a weight of the transparent thermoplastic resin of an aromatic vinyl compound, 10 to 30% by weight relative to the weight of the transparent thermoplastic resin of a vinyl cyanide compound, and greater than 0% up to 15% by weight relative to the weight of the transparent thermoplastic resin of (meth)acrylic acid alkyl ester; 
 a second polymerization step of polymerizing by additionally adding 1 to 10% by weight relative to the weight of the transparent thermoplastic resin of the aromatic vinyl compound; and 
 an obtainment step of obtaining a transparent thermoplastic resin. 
 
     
     
       6. The method according to  claim 5 , wherein the first polymerization step is performed at 100 to 130° C. 
     
     
       7. The method according to  claim 5 , wherein the second polymerization step is performed at 130 to 150° C. 
     
     
       8. The method according to  claim 5 , wherein each of the first and second polymerization steps is performed for one to four hours. 
     
     
       9. The method according to  claim 5 , wherein a total content of the aromatic vinyl compound added during the first and second polymerization steps is 50 to 80% by weight. 
     
     
       10. The method according to  claim 5 , wherein the polymerization is bulk polymerization, suspension polymerization, or emulsion polymerization. 
     
     
       11. The method according to  claim 5 , wherein the aromatic vinyl compound is one or more selected from the group consisting of styrene, a-methylstyrene, p-methyl styrene, o-ethylstyrene, p-ethylstyrene, and vinyltoluene. 
     
     
       12. The method according to  claim 5 , wherein the vinyl cyanide compound is one or more selected from the group consisting of acrylonitrile, methacrylonitrile, and ethacrylonitrile. 
     
     
       13. The method according to  claim 5 , wherein the (meth)acrylic acid alkyl ester is one or more selected from the group consisting of (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid decyl ester, and (meth)acrylic acid lauryl ester. 
     
     
       14. A transparent thermoplastic resin composition, comprising:
 greater than 5% by weight and less than 65% by weight relative to a weight of the transparent thermoplastic resin composition of a transparent thermoplastic resin that comprises a random copolymerization block prepared by polymerizing 50 to 80% by weight relative to a weight of the transparent thermoplastic resin of an aromatic vinyl compound, 10 to 30% by weight relative to the weight of the transparent thermoplastic resin of a vinyl cyanide compound, and greater than 0% up to 15% by weight relative to the weight of the transparent thermoplastic resin of (meth)acrylic acid alkyl ester, and an aromatic vinyl compound block prepared by polymerizing 1 to 10% by weight relative to the weight of the transparent thermoplastic resin of an aromatic vinyl compound; and 
 greater than 35% by weight and less than to 95% by weight relative to the weight of the transparent thermoplastic resin composition of an aromatic vinyl compound-conjugated diene-based compound block copolymer. 
 
     
     
       15. The transparent thermoplastic resin composition according to  claim 14 , wherein the aromatic vinyl compound-conjugated diene-based compound block copolymer comprises 10 to 90% by weight of a conjugated diene-based compound. 
     
     
       16. The transparent thermoplastic resin composition according to  claim 14 , wherein the conjugated diene-based compound is one or more selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and chloroprene. 
     
     
       17. The transparent thermoplastic resin composition according to  claim 14 , wherein the transparent thermoplastic resin composition has a transparency (haze) of 2.0 or less. 
     
     
       18. The transparent thermoplastic resin composition according to  claim 14 , wherein the transparent thermoplastic resin composition has a transmittance (Tt) of 89.9%. 
     
     
       19. The transparent thermoplastic resin composition according to  claim 14 , wherein the transparent thermoplastic resin composition has an impact strength of greater than 10.6 kgf·cm/cm. 
     
     
       20. The transparent thermoplastic resin composition according to  claim 14 , wherein the (meth)acrylic acid alkyl ester is one or more selected from the group consisting of (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid decyl ester, and (meth)acrylic acid lauryl ester.